1. Field of the Invention
This invention relates to shipping containers, and more particularly, to temperature stabilizing, environmental containers especially adapted for the shipment of various specimens as samples which must be maintained within a predetermined temperature range for a given period of time while in transit.
2. Description of the Prior Art
A portable refrigerated container for preserving in cooled conditions various food stuffs and beverages is known from U.S. Pat. No. 2,496,296. The container there described has one or more smaller containers therein which may be positioned as desired and which constitute one or more ice-filled dividing walls, or which may serve as cooling linings for the enclosing walls of the main container. These smaller containers provide cooling surfaces for the material to be cooled and carried in the main container and which may be stored against cooling surfaces of the smaller containers, the latter also serving to cool the air in the main container. The main container is manufactured of molded plastic composition having insulating characteristics.
FIG. 2 of U.S. Pat. No. 2,496,296 illustrates several refrigerant containers supported in the main container by ribs 16 and spaced apart to allow the items to be cooled to be placed between the refrigerant containers. FIG. 8 illustrates refrigerant containers 18' supported on tracks 34 extending along opposite sides of the interior of the main container for selective positioning therein.
A container of the general class described is also disclosed in U.S. Pat. No. 2,989,856. According to the teaching of this patent, a container is formed of corrugated board panels and has grids which comprise blocks of light weight material or the like each of which is filled with a chemical which will absorb or liberate heat for maintaining materials in transit within a given temperature range.
While the containers thus referred to may serve the particular purposes for which they are intended, there is need for a special container for the shipment of certain types of specimens which must be maintained at a temperature in the range of about 0.degree. to 4.degree. C. for at least 80 hours, while being able to protect the contents against physical damage. None of the containers mentioned above are suitable for these purposes.
U.S. Pat. No. 4,292,817 discloses a shipping assembly whereby wastewater samples or the like can be shipped at pre-determined temperatures, the assembly comprising a plurality of liquid retention members and temperature control means. The container includes both an outer protective layer and an inner insulating layer. The outer protective layer and the insulating layer define a shipping cavity containing the liquid retention members and the temperature control means. The liquid retention members are removably positioned in the shipping cavity such that at least one surface of each of the liquid retention members is in direct contact with at least one surface of the temperature control means. The temperature control means are said to be positioned in the shipping cavity such that the temperature of each of the liquid retention members can be controlled below predetermined levels. The disclosed assembly is somewhat limited in the amount of specimen containers it can accommodate and requires specially formed coolant containers.